Fuel vapors can be problematic in the fuel-supply system for internal combustion engines, especially those of the type in which the fuel is injected with a fuel injector. Fuel vapors are unpredictable and their concentration in the fuel supply system varies. The unpredictability of the vapors causes the charge former to deliver fuel in a ratio to the air which may be leaner or richer than desired, resulting in poor engine performance.
It the past, fuel-vapor separators have been provided along the fuel supply path to separate at least part of the vapor from the liquid fuel. This vapor is typically routed into a intake system of the engine for combustion with the incoming air and fuel charge. The routing of the vapor to the intake system, however, also effects the ratio of the air/fuel charge from that which is intended.
Further, the fuel supply system may be used with an engine positioned in a small confine, such as the cowling of an outboard motor. In these situations, space may be at a premium such that the fuel supply system need be as small and simple in arrangement as possible. The need for a complex vapor routing system may occupy too great of space.
A principal object of the present invention is to provide a fuel supply system for an internal combustion engine, the fuel supply system arranged to reduce the transmission of vapor to the charge former(s) of the engine. Another object of the present invention is to provide such a fuel supply system which has a compact arrangement.